The crop-selective herbicidal agent 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidiny l)urea is described in U.S. Pat. No. 5,009,699. This sulfamoyl urea compound demonstrates a superior margin of safety toward crop plants, especially rice plants, while concomitantly controlling broadleaf weeds and sedges.
4-Halo-2'-nitrobutyrophenone compounds and their preparation via the reaction of dihydro-3-(o-nitrobenzoyl)-2(3H)-furanone and a hydrogen halide is described in U.S. Pat. No. 4,075,346. However, this patent does not describe 4-hydroxy-2'-nitrobutyrophenone or tetrahydro-2-(o-nitrophenyl)-2-furanol or mixtures thereof. It has now been found that 4-hydroxy-2'-nitrobutyrophenone or tetrahydro-2-(o-nitrophenyl)-2-furanol or mixtures thereof are useful in the preparation of 4-halo-2-nitrobutyrophenone compounds, important intermediates in the preparation of the crop-selective herbicidal agent 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidiny l)urea.
It is been an object of the present invention to provide 4-hydroxy-2'-nitrobutyrophenone and tetrahydro-2-(o-nitrophenyl)-2-furanol and mixtures thereof.
It is also an object of the present invention to provide a method for the preparation of 4-halo-2'-nitrobutyrophenone compounds, useful intermediates in the preparation of the sulfamoyl urea crop-selective herbicidal agent.
These and other objects of the invention will become more apparent from the detailed description set forth below.